3rd trim sleep on back

Any mummies slept on their back @ 3rd trimester and nothing bad happened? Some days i cant help but to sleep on my back just so i can get longer & more comfortable sleep. As sleeping on my sides, i will tend to get stomach cramps due to weight of the tummy and sometimes shoulder pain. Or sometimes i sleep on either side but woke up to sleeping on my back. (Pls dont recommend me pregnancy pillow) #FTM